add exec action for keys users can now exec command on specifics keys. For example: match class Something on "C-<F5>" do exec my-program

improved error messages yyerror now is a printf-like variadic function. This helps to generate custom error message like "invalid keysym %s" or "invalid key %s" during parsing.

tabify

add ``match *'' to match everything Rationale: sometimes it can be useful to globally bind a key. For instance, some users may like to bind on "C-<Up>" do "<Page_Up>" for every application.

add an error handler the default error handler violates the pledge "stdio" by trying to read (and possibly also write after) some files. Also, I don't like my program to be randomly killed if I try to get class hints on a window that doesn't have any.

initial commit